TeX source:
\begin{array}{crclcl} & -2x^2 &=& -20x & \vert & +20x \cr & -2x^2+20x &=& 0 \cr & x(-2x+20) &=& 0 \cr \text{Faktor 1:} & x_1 &=& 0 \cr\cr \text{Faktor 2:} & -2x_2+20 &=& 0 \cr & x_2 &=& 10 \cr \cr & \mathbb{L} &=& \{0;10\} \end{array}